I don't know a certain path for Boeing. Obviously in this case they need to deal with their internal reporting on the factory floor and be even less trusting of Spirit, but that leads to other problems.
Had the ET-302 reporting accurately represented how the situation developed following the preliminary report on Lion Air, they would not now be buried under an avalanche of blame.
Clearly this manufacturing issue is all on Boeing and they deserve a beating for it; blaming them for the actions of an airline that knew of a design defect but took no measures to cope?
The CEO needs to put his desk on the factory floor of Renton for the next 6 months. As unpleasant as it might be, probably a weekly factory walkaround invite to Dominic and buy 30 minute info-mercials in the Seattle market talking with the floor workers and inspectors about how work is going. These need to be unscripted without a single marketing person within a mile of the building, not even a slick intro. If they think the plant isn't a good backdrop? I'd say that is a sign it needs to be dealt with.